Reciprocating pump



June 24, 1958 c, w. MEADER 2,840,001

RECIPROCATING PUMP Filed March 29, 1956 v 4 Sheets-Sheet, 1

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i C w J L N T {N I E June 24; 1958 c. w. MEADER RECIPROCATING PUMP Filed March 29, 1956 4 Sheets-Sheet 2 June 24, 1 958 c. w. MEADER RECIPROCATING PUMP 4 Sheets-Sheet 4 Filed March 29, 1956 mm Ii- I N W 8W\ MN M vmw 8 \\N\\\\\ 4\\\\\\\\\\\\\\\\\\\-\\\\ N 7 I United States Patent RECIPROCATING PUMP Campling William Meader, Totland Bay, Isle of Wight, England, assignor to Henry Balfour & Co. Limited, Leven, Fife, Scotland, a corporation of Great Britain Application March 29, 1956, Serial No. 574,689

2 Claims. (Cl. 103-48) This invention relates to reciprocating pumps capable of use for pumping thick semi-liquid substances and small solid materials herein collectively referred to as mud.

The invention is concerned with a reciprocating pump including a chamber for the mud, a cylinder open at one end and axially movable through the chamber, a first piston axially movable within the cylinder, driving means to move the cylinder towards and away from a discharge aperture in the wall of the chamber, and driving means to move the piston axially within the cylinder, the driving means to move the cylinder axially towards and away from the discharge aperture comprising a second and fixed cylinder, a second piston axially movable within said second cylinder, a rigid connection between the second piston V and the movable cylinder, means to supply pressure fluid alternately to opposite sides of the second piston, and means to connect to exhaust the side of the second piston opposite to that connected to the supply of pressure fluid.

According to the present invention an annular seal abuts on the inner wall of the chamber, presents an aperture registering with the discharge aperture in the wall of the chamber and is adapted to enter the open end of the axially movable cylinder on the forward stroke of said cylinder.

A reciprocating pump according to the present invention is illustrated in the accompanying drawings in which:

Figs. 1 and 1A are collectively a side elevation of the pump.

Figs. 2 and 2A are collectively a section on a horizontal plane containing the axis of the pump.

Referring to the drawings, 2 denotes a part-cylindrical chamber supported on a frame 1 and having an opening at the top for inlet of mud to be pumped from a hopper 3.

One end wall 4 of the chamber 2 is formed with a discharge aperture 5. A tapered pipe 6 extends from the aperture 5. The outward end of the tapered pipe 6 is connected to a discharge pipe (not illustrated) through a non-return valve (not illustrated).

9 denotes an annular seal which abuts on the inside of the wall 4 and presents an aperture registering with the discharge aperture 5. The seal 9 is adapted to enter the open end 10 of an axially movable cylinder 11.

At the other end of the chamber 2 co-axial therewith and with the discharge aperture is a second and fixed cylinder 12. The cylinder 12 is spaced from the chamber 2 by a pair of spacedplates 2 The movable cylinder 11 is supported in a bearing 13 arranged in an aperture in the other end wall 14 of the chamber 2. The cylinder 11 is slidable from a position between the plates 2 to a position (shown in Figs. 2, 2A) in which the seal 9 enters the open end of said cylinder 11 and serves to prevent leakage of mud from the cylinder 11 to the interior of the chamber 2.

Within the movable cylinder 11 is a first piston 15. The rear of the movable cylinder 11 is connected by operating rods 16 to a second piston 16 slidable in the fixed cylinder 12. A piston rod 17 for the first piston extends through a bearing 18 in the second piston 16,

Patented June 24, 1958 2. through a bearing 18 arranged in an aperture in the front wall 1'2 of the fixed cylinder 12 and through a bearing 2 arranged in an aperture in the rearwall 11" of the movable cylinder 11. The end of the piston rod 17 remote from the first piston 15 is secured to a third piston 19 also slidable in the fixed cylinder 12. The third piston 19 is tapered, the salient face of said piston 19 being towards the second piston 16 to form,- when the cylinder 11 is at the end of its forward stroke, a space 21 between the second piston 16 and the third piston 19.

The third piston 19 is mounted on one end of a tail rod 20 co-axial with and integral with the piston rod 17. The other'end'of the tail rod 20 projects rearwardly from tzhe fixed cylinder 12 and is carried in a tail rod bearing The space between the second piston 16 and the third piston 19, when the movable cylinder 11 and the first piston 15 are withdrawnfully from the discharge aperture 5, communicates through a connection 22 with a valveco'ntr-olled supply of pressure fluid. The space 23 between the second piston 16 and the end wall 12' communicates through a connection 24 with a valve-controlled inlet and eXh'alllSt for pressure 'fl'l'li'd. The space 21 between the second piston '16 and the third piston 19in th'eposition in which the end 10 of the movable cylinder 11 surrounds the seal 9 communicates through a connection 26 with a valve-controlled exhaust for the pressure fluid.

The space 27 behind the third piston 19 communicates through a connection 28 in the rear wall 29 of the cylinder 12 with a valve-controlled inlet and exhaust for pressure fluid.

In operation, the movable cylinder 11 and the first piston 15 are moved to a position between the plates 2. Mud is fed from the hopper 3 to the chamber 2. Pressure fluid is supplied through the connection 22 to the space between the second piston 16 and the third piston, 19, whereby the second piston 16 is moved forwards and the movable cylinder 11, secured thereto by the rods 16*, is moved into the chamber 2 until its open end 10 surrounds the seal 9. During this forward movement the cylinder 11 is charged with mud.

The supply of pressure fluid is then cut OE and pressure fluid is supplied through the connection 28 to the space 27 behind the third piston 19. The space between the second piston 16 and the third piston 19 is placed in communication with exhaust through the connection 26. The third piston 19 is moved forward driving with it the first piston 15 within the movable cylinder 11. The first piston 15 rams the mud through the aperture 5 and the tapered pipe 6 into the discharge pipe for the mud via the automatic non-return valve. 7

When the third piston 19 has reached its extreme forward position, the supply of pressure fluid to the space 27 is cut off and the space 27 behind the third piston 19 is placed in communication with exhaust while the space 23 between the second piston 16 and the end wall 12 is supplied withv pressure fluid through the connection 24. The second piston 16 and the third piston 19 are then moved together, carrying with them the movable cylinder 11 and the first piston 15 to their extreme retracted position.

More mud from the hopper 3 falls into the chamber 2 in front of the movable cylinder 11 and the cycle of operations is repeated. When the hopper 3 is full of mud, the chamber 2 is sealed from the atmosphere, so that, when the movable cylinder 11 is withdrawn from the aperture 5 after discharge of its load, a partial vacuum is formed, and the contents of the hopper 3 are sucked downwards into the chamber 2 ready to be cut into by the movable cylinder 11 during its succeeding forward movement. The cycle of operations can be controlled from a single rotatable valve as will be understood by those skilled in the art. a

It will be understood that the cycle of operations may alternatively be controlled by means of piston type valves, therebeing one piston valve for each movement of, the

.pump. The piston valves may be operatedin sequence by means of contacts made on completion of each movement ofthe. pump. 'The contacts may operate mechanically, electrically, or hydraulically asis wellknown in cesses formed for this purpose for example in the bearing '13 for the movable cylinder 11 and around the discharge aperture 5.

If necessary, the pressure of the fluid used for this purpose may be increased by means of an hydraulic intensifier or other similar means.

What is claimed is:

1. In a reciprocating pump for pumping mud, a chamber for the mud, a cylinder open at one end and axially movable through said chamber, one wall of said chamber having a discharge aperture therein, a piston axially movable within said cylinder, driving means to move said cylinder axially towards and away from said discharge aperture, and driving means to move said piston axially lar form mounted on the wall of said chamber surrounding said discharge aperture, said seal having a cylindrical portion having an outside diameter slightly less than the inside diameter of said cylinder and projecting inwardly from said wall to be received in sealing engagement with the inner surface of said cylinder when said cylinder is moved to cause the open end thereof to surround said discharge aperture.

2. A reciprocating pump as claimed in claim 1 in which the driving means for the said movable cylinder and piston comprises a fixed cylinder spaced axially from said chamber and having two pistons operating therein, one of said pistons being operatively connected by a centrally disposed piston rod to the piston within the movable cylinder, and the other of said pistons being connected to said movable cylinder by means of a plurality of rigid operating rods disposed on opposite sides of said first piston rod.

References Cited in the file of this patent UNITED STATES PATENTS 2,667,841 Meader Feb. 2, 1954 FOREIGN PATENTS 517,766 Belgium Mar. 14, 1953 

